Method and apparatus for the production of bitumen blocks

ABSTRACT

A method and an apparatus for the production of bitumen blocks, with a drop former for generating bitumen drops from molten bitumen, with a belt cooler having a rotating belt for cooling and solidifying the bitumen drops deposited on the rotating belt into tablets, and with a decanting device for decanting the tablets into bags, the tablets being at least partially combined, inside the bags filled with tablets, into a compact bitumen mass.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of German Application No. 10 2013 226 373.2, filed on Dec. 18, 2013, the disclosure of which is hereby incorporated by reference in its entirety into this application.

FIELD OF THE INVENTION

The invention relates to a method and an apparatus for the production of bitumen blocks.

BACKGROUND OF THE INVENTION

For the purposes of this invention, the term “bitumen” designates coldtar pitch, bitumen with fillers and pure bitumen. Soft bitumen, which has a very low softening point in the ring-and-ball test (RaB) according to DIN EN 1427 and high penetration values under needle penetration according to DIN EN 1426, has hitherto been poured in the liquid state into barrels or thermally stable bags. There is the problem, in the case of both barrels and thermally stable bags, that these do not melt down and the bitumen therefore has to be removed from the barrel or bag before further processing. Where bags are concerned, these have to be cut open and removed manually. Furthermore, it is known to form boards from soft bitumen and then in each case shrink a plurality of boards in one bag. Such a bag may be capable of melting down. Both when liquid bitumen is poured into barrels or bags and when bitumen boards are produced, there is the problem that it is scarcely possible to adhere exactly to a stipulated filling quantity or a stipulated filling weight.

SUMMARY OF THE INVENTION

By virtue of the invention, a method and an apparatus for the production of bitumen blocks are to be improved.

The problem on which the invention is based is solved by means of a method for the production of bitumen blocks, in particular made of bitumen with penetration values according to DIN EN 1426 of more than 10 decimillimeters, having the following steps:

-   -   forming of bitumen drops from molten bitumen in a drop former,     -   depositing of the bitumen drops on a rotating belt of a belt         cooler,     -   solidification of the bitumen drops on the belt of the belt         cooler into tablets,     -   removal of the tablets from the belt, and     -   decanting of the tablets into bags, the tablets being at least         partially combined inside the bags into a compact bitumen mass.

In a development of the invention, the pressing of the bags filled with tablets into a desired shape takes place.

In a development of the invention, the pressing of the bags filled with tablets takes place with a pressure dimensioned such that the tablets are at least partially combined into a compact bitumen mass.

According to the invention, an apparatus for the production of bitumen blocks is also provided, with a drop former for generating bitumen drops from molten bitumen, with a belt cooler having a rotating belt for cooling and solidifying the bitumen drops deposited on the rotating belt into tablets, and with a decanting device for decanting the tablets into bags, the tablets being at least partially combined inside the bags filled with tablets into a compact bitumen mass.

In a development of the invention, a moulding press is provided, in order to give the bags filled with tablets a desired shape.

The generation of tablets from bitumen and the decanting of these tablets into bags has the considerable advantage that, on the one hand, bitumen with high penetration values and with a low softening point can also be decanted when cold and therefore standard bags can be used. In particular, these bags do not have to be temperature-resistant, and, for example, packaging, without the subsequent sealing and shrinking of the bags, is also possible. The bags can be produced from melt-down material, so that, in the further processing of the bitumen tablets, the bags can at the same time be melted down. On the other hand, the cold decanting of individually separated tablets enables the filling quantity to be adhered to very accurately. The individual bags can consequently have only very low tolerances in terms of their weight. According to the invention, the bags filled with the tablets can then be brought to the desired shape, for example a parallelepipedal shape, in a moulding press. This makes it easier to stack the bags and ensures that only a little transport space is required when the bags are being transported. It is to the credit of the inventors to have recognized that the production of tablets has so many benefits in terms of the decanting and dimensioning of the filling quantity that it is worth the outlay for tabletting, even if the tablets stick together again in the bags or even the subsequent pressing of the bags into shape takes place as an additional step. In particular, by virtue of the invention, the benefits of easy decanting of the bitumen tablets in the cold state can be combined with the exact shaping of the bags after pressing. At the same time, according to the invention, it is deliberately taken into account that the tablets are at least partially combined with one another in the bags automatically or, where appropriate, during the pressing of the bags filled with tablets, so as to form a compact bitumen mass. In the further processing of bitumen, in particular soft bitumen, it is usually not at all necessary for the tablets still to be in the individually separated state. Surprisingly, however, the tabletting of bitumen, in particular soft bitumen, before decanting nevertheless affords such great benefits that the method of tabletting, decanting and, if appropriate, subsequent pressing of the filled bags into shape is adopted.

In a development of the invention, the moulding press may have at least one press ram.

By means of a press ram, filled bags, which lie, for example, on a conveyor belt, can easily be pressed into a parallelepipedal or other shape.

In a development of the invention, the moulding press has at least one pressure roll.

Filled bags lying, for example, on a conveyor belt can also easily be pressed into a desired shape, for example a parallelepipedal shape, by means of one or more pressure rolls. A parallelepipedal shape is then highly suitable for being stacked on pallets.

In a development of the invention, the moulding press is designed to exert on the bag filled with tablets a pressure dimensioned such that the tablets are combined at least partially into a compact bitumen mass.

The pressing of the bags filled with tablets in a way, that is to say with a pressure and a temperature, such that the tablets are at least partially combined into a compact bitumen mass, seems at first sight to be counterproductive. After all, the bitumen has first been melted down and solidified into tablets and then, in the solidified state, decanted cold into bags. It has been shown, however, that the pressing into shape of the bags filled with tablets is so advantageous in terms of the further transport and further processing of the bitumen that the step of pressing the filled bags into shape, which seems counterproductive per se, is carried out. Furthermore, when the tablets are at least partially combined in the moulding press into a compact bitumen mass, the advantage arises that the bag shape achieved in the moulding press is preserved.

The stacking or further transport of the bags can consequently take place in a very simple way. The pressure exerted by the moulding press is in this case determined and dimensioned as a function of a temperature of the tablets, a material quality of the tablets, in particular the melting point of the tablets, and, if appropriate, an ambient temperature.

In the development of the invention, the decanting device is arranged directly downstream of the belt cooler.

Thus, the tablets removed from the belt do not first have to be stored in a reservoir, but instead can be decanted directly from the belt into bags. This simplifies the set-up of the decanting device at the same time prevents the situation that, particularly in the case of soft bitumen, the tablets are combined again into a compact mass before being decanted.

In the development of the invention, the decanting device has a distributor device with at least one distributor flap and a plurality of distribution paths, in order to conduct tablets removed from the belt to one of a plurality of decanting stations selectively.

Thus, for example, a chute may be provided in the form of one or more inclined planes which lead in each case to a decanting station in each case for a bag. The distributor flap then distributes the tablets removed from the belt cooler to the individual decanting stations, so that sufficient time is available for filling, subsequently closing and transporting away a bag in each case. Advantageously, the decanting device has at least one balance. This may be provided such that the bag to be filled stands on the balance and the filling operation is continued until a desired weight of the filled bag is reached. As already stated, by the tablets being individually separated and solidified, highly accurate adherence to a desired filling quantity or a desired filling rate can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention can be gathered from the claims and the following description of preferred embodiments of the'invention in conjunction with the drawings. Individual features of the embodiments illustrated and of the individual drawings can in this case be combined in any desired way, without going beyond the scope of the invention. In the drawings:

FIG. 1 shows a diagrammatic illustration of an apparatus according to the invention for the tabletting and packaging of bitumen,

FIG. 2 shows a diagrammatic illustration of a moulding press according to a further embodiment of the invention for the apparatus of FIG. 1, and

FIG. 3 shows a diagrammatic illustration of a decanting device according to a further embodiment of the invention for the apparatus of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 illustrates an apparatus 10 for the tabletting and packaging of bitumen, in particular soft bitumen, by means of which the method according to the invention can be carried out. What is designated in this case as soft bitumen is bitumen which, under what is known as “needle penetration” according to DIN EN 1426 “Bitumen and bitumen-containing binders—determination of needle penetration”, has penetration values of 10 dmm (decimillimeters) or more. Hard bitumen, as it is known, usually has penetration values in the range of 2-3 dmm. What is known as soft bitumen, for example for the sealing of roofs, has penetration values of about 20 dmm to 40 dmm. Very soft bitumen qualities for road building lie in the range of 60 dmm to 100 dmm or even higher. What is designated as bitumen in the context of the invention is in this case also bitumen with fillers, in particular with up to 30% fillers, and coldtar pitch, as well as pure bitumen.

The apparatus 10 has a storage tank 12 for liquid bitumen, from which a heated line 14 leads via a pump 16 and a filter 18 to a drop former 20. The drop former is designed as what is known as a rotoform unit and has a rotating perforated outer drum, through which the molten bitumen is pressed by means of a stationary nozzle strip arranged inside the rotating outer drum. The drop former 20 is arranged above a rotating seal belt 22, onto the upper strand of which the bitumen drops 24 generated by means of the drop former 20 are then deposited. The upper strand of the rotating steel belt 22 is cooled from below with cooling water by means of spray nozzles 26. As a result, during the movement of the rotating steel belt 22, clockwise in FIG. 1, the bitumen drops are solidified into tablets on the upper strand of the steel belt 22.

The steel belt 22 is guided via a left-hand deflecting drum 28 and a right-hand deflecting drum 30. At the deflecting drum 30 on the right in FIG. 1, the solidified tablets are then removed from the surface of the steel belt by means of a removal blade 32 and poured directly into a bag 34. The bag 34 is arranged on a rotating conveyor belt 36. The removal blade 32 and the conveyor belt 36 form a decanting device 38, illustrated only diagrammatically in FIG. 1, for bags 34.

The bag 34 filled with tablets can then be conveyed by the conveyor belt 36 of the decanting station 38 to a moulding press 40. There, the filled bag 34 is pressed flat by means of a press ram 42 and is thereby brought to a desired shape which is parallelepipedal here. From the moulding press 40, the then parallelepipedal bags are stacked on pallets 44.

The drop former 20 is covered by means of a hood 48 which prevents bitumen vapours from entering the surroundings. The hood 48 can be provided with a suction-extraction device, not illustrated in FIG. 1. Similarly, the upper strand of the rotating steel belt 22 is provided, downstream of the hood 46, with a hood 48 which also partially covers the decanting station 38. The hood 48, too, is intended to prevent bitumen vapours from entering the surroundings. Above the deflecting drum 30 on the right in FIG. 1, a nozzle 50 fed with liquid or powdery separating agent from a storage tank 54 via a pump 52 is illustrated above the steel belt 22. The powdering or spraying of the solidified tablets on the steel belt 22 is intended to ensure that these can be decanted, still in the individually separated form, in to the bags 34 and, for example, do not already combine with one another again in the region of the removal blade 32. For this purpose, the removal blade 32 may also be cooled.

At the deflecting drum 28 on the left in FIG. 1, a further nozzle 56 is also provided upstream of the drop former 20 in the direction of rotation of the deflecting drum 28 and is fed with separating agents from a storage tank 60 via a pump 58. By means of the nozzle 56, the separating agent, in particular liquid separating agents, can be sprayed onto the steel belt 22. A separating agent film is thereby formed on the steel belt and then prevents the liquid bitumen drops 24 deposited onto the steel belt 22 by the drop former 20 from sticking to the surface of the steel belt.

The spray nozzles 26, by means of which the underside of the upper strand of the steel belt 22 is sprayed with cooling water, are arranged inside a collecting basin, from which the cooling water dripping off again from the underside of the steel belt 22 is led to a collecting tank 62. Starting from the collecting tank, the cooling water is then conveyed via a pump 64 and a heat exchanger 66 to the spray nozzles 26 again.

By means of the apparatus 10 according to the invention, bitumen, particularly soft bitumen, can easily be poured in the form of solidified tablets into bags 34, and since the bitumen is poured in the form of solidified tablets into the bags 34 a stipulated filling amount and a stipulated filling weight of the bags 34 can be adhered to without difficulty. Furthermore, the bags 34 can be formed from material which is not temperature-resistant, since the bitumen is, of course, decanted cold in the form of solidified tablets. The bags 34 can therefore be composed of melt-down material, and the bitumen can be melted down, for example, together with the bags 34 during further processing.

In the moulding press 40, the filled and closed bags 34 can then be pressed into a desired shape. What is in this case taken into account is the process which at first seems counterproductive, to be precise one in which the bitumen tablets are combined at least partially into a compact bitumen mass as a result of the pressing operation. However, the at least partial combining of the tablets into a compact bitumen mass has, in turn, the advantage that the pressed bags preserve their shape. Even during the further processing of the bitumen poured into the bags 34, an at least partial combining of the tablets into a compact mass does not cause any trouble. Yet the benefits of the very simple decanting of the solidified tablets into bags 34 can be utilized.

Even if the moulding press 40 is not employed, the tablets, after being decanted into the bags 34, are combined at least partially into a compact bitumen mass. The outlay for the previous tabletting is nevertheless worthwhile, because, surprisingly, major benefits in terms of packaging to the bags 34, the quality of the bags 34 and accurate adherence to the filling quantity of the bags 34 are afforded.

The illustration in FIG. 2 shows a diagrammatic illustration of a moulding press station 70 according to a further embodiment of the invention. The moulding press station 70 can be used instead of the moulding press station 40. In contrast to the moulding press station 40, the moulding press station 70 has two pressure rolls 72, by means of which the filled bag 34 is pressed into the desired shape.

The illustration in FIG. 3 shows a further embodiment of a decanting device 74. The decanting device could be used instead of the decanting device 38 in FIG. 1. By means of the decanting device 74, two bags 34 can be filled, each of the bags 34 being arranged in each case on a balance 76 and 78. When the desired filling weight of the bags 34 is reached, a distributor flap 80 is changed over by means of a control, not illustrated, so that bitumen tablets then arrive only at the bag which is on the left or on the right in rig. 3. The distributor flap 80 is arranged in the switch region of a chute which has two distribution paths, a first distribution path, which leads to the left to a bag 34 in FIG. 3, and a second distribution path, which leads to the bag 34 on the right in FIG. 3. 

1. Method for the production of bitumen blocks, in particular made from bitumen with penetration values according to DIN EN 1426 of more than 10 decimillimeters, having the steps: forming of bitumen drops from molten bitumen in a drop former, depositing of the bitumen drops on a rotating belt of a belt cooler, solidification of the bitumen drops on the belt of the belt cooler into tablets, removal of the tablets from the belt, and decanting of the tablets into bags, the tablets being at least partially combined, inside the bags filled with tablets, into a compact bitumen mass.
 2. Method according to claim 1, Including pressing the bags filled with tablets into a desired shape.
 3. Method according to claim 2, including pressing the bags filled with tablets with a pressure dimensioned such that the tablets are at least partially combined into a compact bitumen mass.
 4. Apparatus for the production of bitumen blocks, in particular bitumen with penetration values according to DIN EN 1426 of more than 10 decimillimeters, with a drop former for generating bitumen drops from molten bitumen, with a belt cooler having a rotating belt for cooling and solidifying the bitumen drops deposited on the rotating belt into tablets, and with a decanting device for decanting the tablets into bags, the tablets being at least partially combined, inside the bags filled with tablets, into a compact bitumen mass.
 5. Apparatus according to claim 4, wherein a moulding press is provided, in order to give the bags filled with tablets a desired shape.
 6. Apparatus according to claim 5, wherein the moulding press has at least one press ram.
 7. Apparatus according to claim 5, wherein the moulding press has at least one pressure roll.
 8. Apparatus according to claim 1, wherein the moulding press is designed to exert upon the bag filled with tablets a pressure dimensioned such that the tablets are at least partially combined into a compact bitumen mass.
 9. Apparatus according to claim 1, wherein the decanting device is arranged directly downstream of the belt cooler.
 10. Apparatus according to claim 9, wherein the decanting device has a distributor device with at least one distributor flap and a plurality of distribution paths, in order to conduct tablets removed from the belt to one of a plurality of decanting stations selectively.
 11. Apparatus according to claim 1, wherein the decanting device has at least one balance. 